Automatic air-arc gouger



June 25, 1963 c. M. WESTFALL AUTOMATIC AIR-ARC cousan 3 Sheets-Sheet 1Filed June 2, 1961 & '22

3 Sheets-Sheet 2 Filed June 2, 1961 MSW h www June 25, 1963 c. M.WESTFALL AUTOMATIC ummc GOUGER 3 Sheets-Sheet 3 Filed June 2, 1961 @0671m Zggawi 3,095,520 Patented June 25, 1963 3,095,520 AUTOMATIC AIR-AR!)GOUGER Clifford M. Westfall, Peotone, Ill., assignor to Chicago Bridge8: Iron Company, Chicago, llL, a corporation of Illinois Filed June 2,1961, Ser. No. 114,470 8 Claims. (Cl. 314-) The present inventionrelates generally to apparatus for preparing plates which are to bewelded'in edge-toedge relation, and more particularly to apparatusutilizing a carbon arc in conjunction with an air stream for gouging outa weldment-receiving channel along the junction between the edges ofthese plates.

In the construction of storage tanks, hoppers and the like, a pluralityof plates are positioned in end-to-end relation and tacked or keyed inthis position preparatory to welding along the junction between theseplates. Heretofore, when these plates were placed in the preparatoryposition, it was necessary to space them a predetermined degree andbevel the edges beforehand to accommodate the weldment.

According to the present invention, edge spacing and beveling is nolonger required and steel plates may be used as received from therolling mill. More specifically, the present invention provides a carbonarc to burn a channel approximately halfway through said plates alongthe junction thereof, and a stream of air to blow the molten metal andslag out of the burned area leaving a clean channel to accommodate theWeldment. This airare gouger is moved along the seams of the tank,hopper, or other workpiece by a conventional carriage such as that usedto similarly carry seam-welding equipment, such carriages being wellknown to those skilled in the art (see Arnold US. Patent No. 2,713,106,issued lune 12, 1955).

A feature of the present invention is apparatus for automaticallyfeeding a continuous succession of carbon rods to the burning zone. Morespecifically, the subject invention provides means for continuouslyfeeding a carbon rod to the burning zone, means. for ejecting theburned-down stub of the carbon rod after the latter has beensubstantially consumed, and means for automatically replacing theburned-down stub with a new carbon rod.

Other features and advantages are inherent in the structure claimed anddisclosed, as will be apparent to those skilled in the art from thefollowing detailed description in conjunction with the accompanyingdrawings wherein:

FIGURE 1 is a plan view of an automatic air-arc gouger constructed inaccordance with the present invention, and diagrammatically illustratinga pneumatic system therefor;

FIGURE 2' is a partially fragmented elevational view of the automaticair-arc gouger of FIGURE 1;

FIGURE 3 is a vertical sectional view taken substantially along line 3-3of FIGURE 1, with portions of the pneumatic system removed for clarityof illustration;

FIGURE 4 is a sectional view taken substantially along line 44 of FIGURE2, with portions of the pneumatic system removed; and

FIGURE 5 is a schematic view of the electrical circuitry for controllingthe operation of the subject gouger.

Referring initially to FIGURES 3 and 4, there is shown an embodiment ofthe subject invention indicated generally by the numeral 19 andcomprising a tubular barrel 12 having an upper slot 13 communicatingwith a magazine 14 holding a plurality of vertically stacked carbon rods15. The lowermost of the carbon rods, 15a, drops through slot 13 intobarrel 12 and is advanced forwardly through the barrel (to the right inthe figures) by an elongated pusher 16 mounted for back-and-forthmovemeat in a longitudinally slotted tube or cylinder 17 located inaxial alignment with barrel 12 and to the rear thereof (to the left inthe figures). Pusher 16 advances rod 15a forwardly so that the tip 20 ofthe rod extends outwardly through a pair of jaws 18, 19, which aws engage the rod and electrically connect the latter to a power source forproducing the gouging arc.

The rod tip 20 is steadily advanced toward the unction or seam between apair of end-to-end plates (not shown) and, upon arcing, burns out achannel as the entire apparatus is moved along the seam by aconventional carriage (not shown). A stream of air is directed from anexternal air line through a channel 139 in jaw 19 toward the area longthe seam burned out by the tip 20 of the carbon rod, said stream of aircleaning out the molten metal and/ or slag particles in the burned-outarea to leave a clean channel for receiving a weldment.

When the carbon rod has burned down toa stub 15b (dash-dot lines),forward motion of pusherlti is automatically stopped, jaws 18, 19 areautomatically disengaged, stub 15b is automatically ejected, and pusher16 is then retracted until the forward end thereof (to the right in thefigures) clears the rearward end of slot 13 (to the left in thefigures), thereby allowing a new carbon rod 15 to automatically dropinto place in barrel l2, whereupon pusher 16 is again advanced to feedthe new rod into a position to gouge outa channel.

Defining the entire structure now in greater detail, pusher 16 is shownto comprise sugear rack having a plurality of teeth 22 along one sidethereof, said teeth being drivingly engaged by a pinion gear 23 mountedon a shaft 24 connected to the driven side of an electromagnetic clutch25, the driving side of which is connected to a speed reducer 26 drivenby an electric motor 27 mounted thereabove (FIGURESJ and 2).

At the rear end of pusher 16 (to the left in the figures) there isattached a bracket 39 connected by a coupling 31 to a forwardlyextending piston rod 32 terminating at a piston 33 enclosed within apusher-actuating cylinder 34 Located adjacent the forward end ofcylinder 34 (to the right in the figures) is an irregularly shaped plate40 upon which is mounted a jaw-actuating cylinder 41 from the forwardend of which extends a piston rod 42 pivotally connected at 43 to atriangular-shaped plate or hell crank 44 pivoted at 45 on a flange 138extending from a collar 239 mounted on barrel 12. Bell crank 44 is alsopivotally connected at 46 to a link 47 attached to jaw 18.

Pusher 16 and piston rod 32 are linked to move forward and backwardtogether. Jaw 18 opens and closes in response to movement of piston rod42. Forward movement of piston rod 42 moves jaw 18 to a closed positionfor engaging a carbon rod between jaws 18 and 19. Jaw 19 is electricallyconnected to a power source by a cable inside air line 140; and when thecarbon rod is engaged between the jaws, current flows through jaw 19 tothe rod to produce the arc betweenjthe rod and the workpiece. Airflowing through line 140 cools the power cable. Rearward movement ofpiston rod 42 opens jaw 18 and disengages both jaws from the carbon rod.

The description of a typical cycle of' operation may start with theelements in the positions shown in FIG- URES 3 and 4. In these figurespusher 16 is at an intermediate station between extended and retractedpositions thereof, and at this station a cam or projection 37 on bracket30 has engaged and depressed a switch arm 101 (FIGURE 5) on a switch195, thereby actuating a relay 102, in turn causing the energization ofelectro magnetic clutch 25 as well as the actuation of solenoid valvesA, B and D (FIGURES 1, 2 and 5). As previously indicated, energizationof clutch '25 turns gear 23 which engages the teeth 22 on pusher 16,thereby causing the latter to advance forwardly at a steady rate ofspeed, pushing rod 15a forwardly through barrel 12.

Referring now to FIGURES 1 and 2, illustrating an embodiment of apneumatic system for operating portions of the subject apparatus, thereis shown a main air line 103 extending through a filter 104, through anair pressure regulator 105 (said regulator having a branch connection toa pressure gauge 107), and to one side of a conventional oiler 106. Theoiler introduces a trace of lubricant into the pneumatic system tofacilitate movement of the valve parts. Extending from the other side ofoiler 106 is a line 118 communicating with one side of a valve C andalso with a second line 108. Line 108 communicates with one side ofvalve B and with an additional line 114 communicating with one side ofvalve A. The other side of valve A is connected by a line 109 to aconnection 110 at the rearward end of jawactuating cylinder 41.Energization of relay 102 opens valve A, thereby causing air to flowthrough valve A, line 109, and connection 110 into the rear end ofcylinder 41, thereby advancing its piston and piston rod 42 in a forwarddirection to close jaw 18 and engage jaws 18, 19 around the carbon rod.

Energization of relay 102 also opens valve D, which is connected bylines 111 and 1.17 to a connection 112 at the forward end of cylinder41. As the piston within cylinder 41 advances forwardly, air escapesfrom the forward end of the cylinder through connection 112, lines 117and 111, and is exhausted through valve D.

As the forwardly moving pusher 16 reaches its extended position at theend of the forward stroke, a cam or projection 38 on bracket 30 engagesand depresses a second switch arm 131 (FIGURE on a switch 196, therebyenergizing a second relay 132 in turn actuating and opening solenoidvalves C and F, while at the same time deenergizing relay 102, saiddeenergization of relay 102 causing valves A and D to close and valve Bto open.

The opening of valve C causes air to flow therethrough, and through aline 119 to a connection 120 at the forward end of barrel 12. Airentering barrel 12 through connection 120 ejects the stub b left thereinat the end of the forward stroke of pusher 16.

At the same time as cam 38 on bracket engages and depresses switch arm131, a projection 39 on bracket 30 depresses a pin 124 on a poppet valve125 connected by a line 126 to a connection 127 on a conventionallyconstructed spool-containing valve E. Opening of poppet valve 125 bleedsvalve E and causes a repositioning of the spool within valve E so thatair entering the latter through a line 115 from the now-open valve Bwill be directed through a connection 116 to line 117 and then toconnections 112, 113 at the forward ends of cylinders 41, 34respectively. This causes movement of respective piston rods 42, 32 in arearward direction (to the left in the figures).

Movement of piston rod 32 in a rearward direction retracts pusher 16.Movement of piston rod 42 in a rearward direction opens jaw 18, therebyfacilitating removal of stub 15b by substantially simultaneous injectionof air through connection 120 at the forward end of barrel 12. Duringthe rearward movement of piston 33 in cylinder 34 air is exhausted fromthe rear of cylinder 34 through connection 122, lines 123 and 121, andopen valve F. Air is exhausted through the rearward end of cylinder 41through connection 110, line 109, and an opening in valve A.

At the conclusion of the rearward stroke, cam 38 on bracket 30 engagesand depresses a switch arm 141 (FIG- URE 5) on a switch 197 to open thecircuit to relay 132, thereby deenergizing the latter and deactuatingsolenoid valves C and F, thus causing the latter two valves to close.Simultaneously, the rear surface 127 of bracket 30 engages a depressablepin 128 on a poppet valve 129 connected by a line 130 to valve E.Opening of valve 129 bleeds valve E to cause a repositioning of thespool within valve E to a position whereby air entering valve E throughline (from the still-open valve B) is directed through connection 137and line 123 to the connection 122 at the rearward end of cylinder 134.This causes forward movement of piston 33 and piston rod 32, in turnadvancing pusher 16 forward to its intermediate station in which thestud 37 on bracket 30 once again engages and depresses the switch arm101.

As previously described, depression of switch arm 101 causesenergization of relay 102 and actuation of valve B so as to close thelatter. Since valve B is closed, air from the main air line can nolonger enter valve E or line 123 or the rear end of cylinder 34. Thusfurther advancement of pusher 16 by pneumatic means is stopped. However,energization of relay 102 also energizes electromagnetic clutch 25 sothat pusher rod 16 is now advanced by the engagement of rotating gear 23with the teeth 22 on the rack-like pusher 16. The advancing pusher 16engages and pushes forward a carbon rod which dropped through the slot13 in the top of barrel 12 to fill up the space vacated by the pusher asit returned to its retracted position.

134 and 136 represent manually actuable poppet valves connected by lines133, 135, respectively, to valves 125, 129, respectively, and provideemergency means for bleeding valve E.

Referring to FIGURE 5, an electrical circuit for the subject apparatuswill now be described in greater detail. The subject apparatus receivesits power from a circuit including main power lines 161, 162 and a mainpower switch 163. Motor 27 is connected in parallel to the main powerlines by a circuit including lines 164, 165, switch 166 and rectifier167.

Describing, now, the circuit for energizing relay 102 the relay coil 189has one terminal 168 normally connected to main power line 162 by line200, terminal 156 on switch 196, switch arm 131, and terminal on switch.196. The other terminal 169 of relay coil 189 is connected by line 201to a terminal 153 on switch 195. Consequently, when pusher 16 reachesits intermediate station, and the arm 101 of switch 195 is moved by cam37 from terminal 154 on switch 195 to terminal 153, the second terminal169 of relay coil 189 becomes connected to main power line 161 by acircuit comprising line 201, terminal 153, switch arm 101, terminal 152on switch 195, line 202, terminal 171 on relay 102, line 203, terminal179 on relay 132, internal line 193 in relay 132, movable contactelement 187 in relay 132, terminal 181 in relay 132, line 204, andterminal on switch 197. With both terminals of its coil 189 thusconnected to respective power lines, relay 102 becomes energized.

Relay .102 remains energized even after switch arm 101 has returned fromits closed position, in contact with terminal 153 on switch 195, to itsnormal open position in contact with terminal 154 on switch 195. Morespecifically, the terminal 168 on relay coil 189 is still connected tomain power line 162 by the circuit previously described. The otherterminal 169 on coil 189 is connected to main power line 161 by line205, terminal on relay 102, movable contact element in relay 102 (saidelement moving into contact with terminal 175 upon energization of relay102), internal line 191 in relay 102, terminal 171 on relay 102, andline 203 which is connected to the main power line 161 by a circuitalready described.

Relay 102 remains energized until arm 131 on switch 196 is moved fromits normal position in contact with terminal 156 on switch 196, saidmovement occurring when pusher 16 reaches its extended position and arm131 is engaged by cam 38. This movement of arm 131 breaks the circuitbetween terminal 156 (connected to coil terminal 168 on relay 102) andmain power line 162, thereby denergizing the coil on relay 102.

The actuation of solenoid valves A, D and B, and

the energization of clutch 25, upon energization of relay 102, is asfollows. When relay 102 is energized, the movable contact elements 184,185 move from terminals 172, 173 respectively to terminals 174, 175respectively. Relay contact 184 is connected to main power line 161 byrelay internal line 190, terminal 170' on relay 102, line 214, terminal181 on relay 132, line 204, and terminal 160 on switch 197. Movement ofcontact element 184 into contact with element 174 connects one side ofeach of the solenoid valves A, D and B, and one side of clutch rectifier188 to main power line 161 by virtue of the connection of terminal 174with lines 208, 209, 206, 207 respectively.

Each of the previously described solenoid valves and the clutchrectifier has another side connected to main power line 162 by thefollowing circuits. Valves B, A and D are connected to terminal 155 onswitch 196 by lines 210, 211, and 212 respectively. Rectifier 188 isconnected to terminal 155 by line 213. As previously described, terminal155 is directly connected to line 162. Accordingly, when relay 102 isactuated to move the contact element 184 into contact with element 174,solenoid valves A and D are opened, solenoid valve B is closed, andcurrent flows through rectifier 188 to energize electromagnetic clutch25. As previously indicated, clutch 25 remains energized and solenoidvalves A, D and B remain actuated until arm 131 on switch 196 is movedout of contact with terminal 156 on switch 196, by the engagement of cam38 with arm 131 when pusher 16 reaches its extended position.

The energization of relay 132 is as follows. The relay coil 192 has oneterminal 177 normally connected to main power line 161 by line 215,terminal 158 on switch 197, switch arm 141, and terminal 160 on switch197. The other relay coil terminal 176 is connected to terminal 157 onswitch 196. As previously indicated, when pusher 16 reaches its extendedposition, cam 38 engages switch arm 131. This moves arm 131 into contactwith terminal 157. As a result, terminal 176 on relay coil .192 becomesconnected to main power line 162 by a circuit including line 216,terminal 157, switch arm 131, and terminal 155 which is directlyconnected to main power line 162; and relay 132 becomes energized.

Energization of relay 132 actuates solenoid valves C and F in the mannerdescribed below. Energization of relay 132 causes movement of thisrelays movable contact elements 186, 187 from relay terminals 180, 181respectively to relay terminals 182, 183 respectively. Terminal 182 isconnected by lines 217, 218 to a respective side of solenoid valves Cand F respectively. Each of these solenoid valves has another sideconnected by lines 219, 220 respectively to terminal 177 on relay 132which in turn is connected to power line 161 by line 215, terminal 158on switch 197, switch arm 141, and terminal 160 on switch 197.Accordingly, movement of contact element 186 into contact with terminal182 connects solenoid valves C and F with both power lines, therebyactuating and opening these valves.

Relay 132 remains energized even after the switch arm 131 has moved backfrom its engagment with terminal 157 on switch 196 to its normalposition in contact with terminal 156 on switch 196, said returnmovement occurring after switch arm 131 has been disengaged from cam 38on bracket 30. More specifically, relay coil terminal 177 is stillconnected to main power line 161 by the circuit including line 215,terminal 158 on switch 197, switch arm 141, and terminal 160. The otherrelay coil terminal 176 is connected to main power line 162 by a circuitincluding line 221, terminal 182 on relay 132, movable contact element186 on relay 132 (moved into contact with terminal 182 upon energizationof relay 132), internal line 194 in relay 132, terminal 178 on relay132, line 222, and terminal 155 on switch 196.

Relay 132 is deenergized when arm 141 on switch 197 is moved from itsnormal position in contact with terminal 158 on switch 197 towardterminal 159 by virtue of the engagement of arm 141 by cam 37 on bracket32, said engagement occurring when the pusher 16 is returned to itsretracted position. Movement of switch arm 141 out of contact withterminal 158 breaks the circuit between coil terminal 177 on relay 132and main power line 161. Accordingly, the relay is deenergized andsolenoid valves C and F are returned to their deactuated condition.There has thus been described an apparatus for gouging out a channel atthe junction between a pair of plates disposed in end-to-end relation,said apparatus utilizing a carbon rod to produce an arc for burning outthe channel and a stream of air for cleaning out the molten metal orslag particles from the burned-out area. In addition, theabove-described apparatus includes, as a primary feature, means forfeeding a continuous succession of carbon rods to the burning zone. Morespecifically, the apparatus comprises means for continuously advancing acarbon rod toward the workpiece as the rod burns down, means forejecting the burned-down stub of the carbon rod after the latter hasbeen substantially consumed, and means for automatically replacing theburned-down stub with a new carbon rod.

The foregoing detailed description has been given for clearness ofunderstanding only, and no unnecessary limitations should be understoodtherefrom, as modifications will be obvious to those skilled in the art.

I claim: 1. In an apparatus for gouging a channel on a metal workpiece:

barrel means for receiving a carbon rod; pusher means at the rearwardend of said barrel means; means mounting said pusher means forreciprocal movement in forward and rearward directions from a retractedposition through an intermediate position to an extended position andthen back to said retracted position; means on said pusher means forengaging the rearward end of said carbon rod when the pusher means movesforwardly from its intermediate position and for advancing the rod in aforward direction, towards an area to be are gouged on the workpiece,when the pusher is moving forward from its intermediate position towardits extended position; jaw means at the forward end of said barrel andactuable to engage said advancing carbon rod;

mechanical driving means actuable in response to attainment by saidpusher means of said intermediate position for advancing the pushermeans from its intermediate position to its extended position at asteady deliberate rate;

first fluid driving means actuable in response to attainment by thepusher means of its extended position for rapidly retracing the pushermeans from its extended position to its retracted position;

and second fluid driving means actuable in response to attainment by thepusher means of its retracted position for rapidly advancing the pushermeans from its retracted position to its intermediate position.

2. An apparatus as recited in claim 1 and comprising:

means responsive to advancement of the pusher means to its intermediateposition for actuating said jaw means to engage said rod;

and means actuable in response to attainment by the pusher means of itsextended position for disengag ing said jaw means from the rod.

3. The apparatus of claim 1 wherein both said jaw actuating means andsaid jaw disengaging means are fluid driven.

4. An apparatus as recited in claim 1 and comprising:

means actuable in response to attainment by the pusher means of itsextended position for ejecting the portion of the carbon rod notconsumed during the arc gouging operation.

5. An apparatus as recited in claim 4 wherein said rod ejecting meanscomprises means for directing a stream of fluid against the rearward endof the carbon rod remaining in said barnel.

6. An apparatus as recited in claim 1 and comprising: means responsiveto advancement of the pusher means through its intermediate position foractuating said jaw means to engage said rod; means actuable in responseto attainment by the pusher means of its extended position fordisengaging said jaw means to engage said rod; and means actuable inresponse to attainment by the pusher means of its extended position forejecting the unconsumed portion of the carbon rod. 7. An apparatus asrecited in claim 6 wherein: both said jaw actuating means and said jawdisengaging means are fluid driven; and said rod ejecting meanscomprises means for directing a stream of fluid against the rearward endof the carbon rod remaining in said barrel.

8. An apparatus as recited in claim 1 and comprising means responsive tothe retraction of the pusher means behind said intermediate positionthereof for introducing a new carbon rod into said barrel means.

References Cited in the file of this patent UNITED STATES PATENTS1,746,208 Alexander Feb. 4, 1930 2,032,240 Westhaver Feb. 25, 19362,531,181 Wilson Nov. 21, 1950 2,706,236 Stepath et al. Apr .12, 19552,784,293 Adams Mar. 5, 1957 2,817,003 Dusek Dec. 17, 1957 2,899,536Hoese, et al. Apr. 11, 1959 UNITED STATES PATENT OFFICE CERTIFICATE OFCORRECTION Patent No. 33395 520 June 25 1963 Clifford M. Westfall It ishereby certified that error appears in the above numbered patentrequiring correction and that the said Letters Patent should read ascorrected below.

a Column 2,, line 14 for "long" read along column 6 line 54 for"retracing read retracting column 7, line 10 strlke out "to engage said"and insert instead from the Signed and sealed this 17th day of December1963.

(SEAL) Attest: EDWIN L. REYNOLDS ERNEST W. SWIDER Attesting Officer Acti 3 Commissioner of Patents

1. IN AN APPARATUS FOR GOUGING A CHANNEL ON A METAL WORKPIECE: BARRELMEANS FOR RECEIVING A CARBON ROD; PUSHER MEANS AT THE REARWARD END OFSAID BARREL MEANS; MEANS MOUNTING SAID PUSHER MEANS FOR RECIPROCALMOVEMENT IN FORWARD AND REARWARD DIRECTIONS FROM A RETRACTED POSITIONTHROUGH AN INTERMEDIATE POSITION TO AN EXTENDED POSITION AND THEN BACKTO SAID RETRACTED POSITION; MEANS ON SAID PUSHER MEANS FOR ENGAGING THEREARWARD END OF SAID CARBON ROD WHEN THE PUSHER MEANS MOVES FORWARDLYFROM IT INTERMEDIATE POSITION AND FOR ADVANCING THE ROD IN A FORWARDDIRECTION, TOWARDS AN AREA TO BE ARC GOUGED ON THE WORKPIECE, WHEN THEPUSHER IS MOVING FORWARD FROM ITS INTERMEDIATE POSITION TOWARD ITSEXTENDED POSITION; JAW MEANS AT THE FORWARD END OF SAID BARREL ANDACTUABLE TO ENGAGE SAID ADVANCING CARBON ROD; MECHANICAL DRIVING MEANSACTUABLE IN RESPONSE TO ATTAINMENT BY SAID PUSHER MEANS OF SAIDINTERMEDIATE POSITION FOR ADVANCING THE PUSHER MEANS FROM ITSINTERMEDIATE POSITION TO ITS EXTENDED POSITION AT A STEADY DELIBERATERATE; FIRST FLUID DRIVING MEANS ACTUABLE IN RESPONSE TO ATTAINMENT BYTHE PUSHER MEANS OF ITS EXTENDED POSITION FOR RAPIDLY RETRACING THEPUSHER MEANS FROM ITS EXTENDED POSITION TO ITS RETRACTED POSITION; ANDSECOND FLUID DRIVING MEANS ACTUABLE IN RESPONSE TO ATTAINMENT BY THEPUSHER MEANS OF ITS RETRACTED POSITION FOR RAPIDLY ADVANCING THE PUSHERMEANS FROM ITS RETRACTED POSITION TO ITS INTERMEDIATE POSITION.